// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_BASE_WIN_ATL_MODULE_H_
#define UI_BASE_WIN_ATL_MODULE_H_

#include <atlbase.h>
#include <atlcom.h>

#include "base/compiler_specific.h"
#include "base/macros.h"

namespace ui {
namespace win {

    // Ensure that we have exactly one ATL module registered. It's safe to
    // call this more than once. ATL functions will crash if there's no
    // ATL module registered, or if you try to register two of them, so
    // dynamically registering one if needed makes it much easier for us
    // to support different build configurations like multi-dll without
    // worrying about which side of a module boundary each ATL module object
    // belongs on.
    //
    // This function must be implemented in this header file rather than a
    // source file so that it's inlined into the module where it's included,
    // rather than in the "ui" module.
    inline void CreateATLModuleIfNeeded()
    {
        if (_pAtlModule == NULL) {
            // This creates the module and automatically updates _pAtlModule.
            new CComModule;
        }
    }

} // namespace win
} // namespace ui

#endif // UI_BASE_WIN_ATL_MODULE_H_
